Flakes: Difference between revisions

Line 3:

== Introduction ==

~~Flakes allow you to specify your code's~~ dependencies ~~(e.g. remote Git repositories) in a declarative way, simply by listing them inside a <code>flake~~.~~nix</code> file:~~

The flakes experimental feature introduces a policy for managing dependencies between Nix expressions and adds supporting convenience functionality.

~~<syntaxHighlight lang=~~nix>

Technically, a [https://nixos.org/manual/nix/unstable/command-ref/new-cli/nix3-flake.html#description flake] is a file system tree that contains a Nix file named <code>flake.nix</code> in its root directory.

{

~~inputs = {~~

~~home~~-~~manager.url = "github:nix~~-~~community~~/~~home~~-~~manager";~~

};

}

</~~syntaxHighlight~~>

~~Each dependency gets pinned, that is: its commit hash gets automatically stored into a file - named <code>flake.lock</code> - making it easy~~ to~~, say, upgrade it~~:

Flakes add the following behavior to Nix:

<~~syntaxHighlight lang=console~~>

# A <code>flake.nix</code> file offers a uniform [https://nixos.org/manual/nix/stable/command-ref/new-cli/nix3-flake.html#flake-format schema], where:

$ nix ~~flake lock~~ --~~update~~-~~input home~~-~~manager~~

#* Other flakes can be referenced as dependencies providing Nix language code or other files.

~~</syntaxHighlight>~~

#* The values produced by the Nix expression in <code>flake.nix</code> are structured according to pre-defined use cases.

# References to other flakes can be specified using a dedicated [https://nixos.org/manual/nix/stable/command-ref/new-cli/nix3-flake.html#flake-references URL-like syntax]. A [https://nixos.org/manual/nix/stable/command-ref/new-cli/nix3-registry.html flake registry] allows using symbolic identifiers for further brevity. References can be automatically locked to their current specific version and later updated programmatically.

~~''(if you're familiar with modern packages managers like <~~code~~>cargo</code>~~ or <code>~~npm~~</code>~~, then the overall mechanism shouldn't surprise you~~ - ~~Nix works in~~ a ~~similar way, although without a centralized repository~~.~~)''~~

# A [https://nixos.org/manual/nix/stable/command-ref/new-cli/nix.html new command line interface], implemented as a separate experimental feature, leverages flakes by accepting flake references in order to build, run, or deploy software defined as a flake.

~~Flakes replace the~~ nix-~~channels~~ command and ~~things like ad~~-~~hoc invocations of <code>builtins.fetchgit<~~/~~code>~~ - ~~no more worrying about keeping your channels~~ in ~~sync~~, ~~no more worrying about forgetting about~~ a ~~dependency deep down in your tree: everything's at hand right inside <code>~~flake~~.lock</code>~~.

== Enable flakes ==

@@ Line 3: / Line 3: @@
 == Introduction ==
-Flakes allow you to specify your code's dependencies (e.g. remote Git repositories) in a declarative way, simply by listing them inside a <code>flake.nix</code> file:
+The flakes experimental feature introduces a policy for managing dependencies between Nix expressions and adds supporting convenience functionality.
-<syntaxHighlight lang=nix>
+Technically, a [https://nixos.org/manual/nix/unstable/command-ref/new-cli/nix3-flake.html#description flake] is a file system tree that contains a Nix file named <code>flake.nix</code> in its root directory.
-{
-  inputs = {
-    home-manager.url = "github:nix-community/home-manager";
-  };
-}
-</syntaxHighlight>
-Each dependency gets pinned, that is: its commit hash gets automatically stored into a file - named <code>flake.lock</code> - making it easy to, say, upgrade it:
+Flakes add the following behavior to Nix:
-<syntaxHighlight lang=console>
+# A <code>flake.nix</code> file offers a uniform [https://nixos.org/manual/nix/stable/command-ref/new-cli/nix3-flake.html#flake-format schema], where:
-$ nix flake lock --update-input home-manager
+#* Other flakes can be referenced as dependencies providing Nix language code or other files.
-</syntaxHighlight>
+#* The values produced by the Nix expression in <code>flake.nix</code> are structured according to pre-defined use cases.
+# References to other flakes can be specified using a dedicated [https://nixos.org/manual/nix/stable/command-ref/new-cli/nix3-flake.html#flake-references URL-like syntax]. A [https://nixos.org/manual/nix/stable/command-ref/new-cli/nix3-registry.html flake registry] allows using symbolic identifiers for further brevity. References can be automatically locked to their current specific version and later updated programmatically.
-''(if you're familiar with modern packages managers like <code>cargo</code> or <code>npm</code>, then the overall mechanism shouldn't surprise you - Nix works in a similar way, although without a centralized repository.)''
+# A [https://nixos.org/manual/nix/stable/command-ref/new-cli/nix.html new command line interface], implemented as a separate experimental feature, leverages flakes by accepting flake references in order to build, run, or deploy software defined as a flake.
-Flakes replace the nix-channels command and things like ad-hoc invocations of <code>builtins.fetchgit</code> - no more worrying about keeping your channels in sync, no more worrying about forgetting about a dependency deep down in your tree: everything's at hand right inside <code>flake.lock</code>.
 == Enable flakes ==